The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

RBTs helped to slash road toll: NSW police

NSW marks the 30th anniversary of random breath testing (RBT) this week with a pledge to keep up the fight against drink-driving over summer.

The late Labor MP George Paciullo was the champion of RBT, which was first conducted in the Sydney suburbs of Granville and Guildford on December 17 1982, at a time when the state's annual road toll stood at 1253.

Thirty years and 85 million RBTs later, there are now 70 per cent fewer deaths on the state's roads, with 364 recorded in 2011, the NSW police department says.

As part of RBT's 30th anniversary, NSW Police Minister Michael Gallacher launched Operation Paciullo last month to honour the former MP.

NSW police officers will perform more than one million RBTs over the summer, having already charged 27 drivers with drink-driving since Operation Paciullo began.

They join more than 545,000 other motorists who have been charged with the offence over the past 30 years.

"Throughout the summer we will be conducting numerous operations, designed to catch dangerous drivers before they hurt or kill themselves or someone else," Assistant Commissioner John Hartley said.